<!DOCTYPE html>
<html>

<head>
  <meta charset="utf-8">
  <title>纯 CSS 实现响应式导航菜单</title>
  <style media="screen">
    .nav {
      position: relative;
      margin: 20px 0;
    }

    .nav ul {
      margin: 0;
      padding: 0;
    }

    .nav li {
      margin: 0 5px 10px 0;
      padding: 0;
      list-style: none;
      display: inline-block;
    }

    .nav a {
      padding: 3px 12px;
      text-decoration: none;
      color: #999;
      line-height: 100%;
    }

    .nav a:hover {
      color: #000;
    }

    .nav .current a {
      background: #999;
      color: #fff;
      border-radius: 5px;
    }
    /* right nav */

    .nav.right ul {
      text-align: right;
    }
    /* center nav */

    .nav.center ul {
      text-align: center;
    }

    @media screen and (max-width: 600px) {
	.nav {
		position: relative;
		min-height: 40px;
	}
	.nav ul {
		width: 180px;
		padding: 5px 0;
		position: absolute;
		top: 0;
		left: 0;
		border: solid 1px #aaa;
		background: #fff url(images/icon-menu.png) no-repeat 10px 11px;
		border-radius: 5px;
		box-shadow: 0 1px 2px rgba(0,0,0,.3);
	}
	.nav li {
		display: none; /* hide all <li> items */
		margin: 0;
	}
	.nav .current {
		display: block; /* show only current <li> item */
	}
	.nav a {
		display: block;
		padding: 5px 5px 5px 32px;
		text-align: left;
	}
	.nav .current a {
		background: none;
		color: #666;
	}

	/* on nav hover */
	.nav ul:hover {
		background-image: none;
	}
	.nav ul:hover li {
		display: block;
		margin: 0 0 5px;
	}
	.nav ul:hover .current {
		background: url(images/icon-check.png) no-repeat 10px 7px;
	}

	/* right nav */
	.nav.right ul {
		left: auto;
		right: 0;
	}

	/* center nav */
	.nav.center ul {
		left: 50%;
		margin-left: -90px;
	}

}
  </style>
</head>

<body>

  <nav class="nav">
    <ul>
      <li class="current"><a href="#">HTML</a></li>
      <li><a href="#">CSS</a></li>
      <li><a href="#">JavaScript</a></li>
      <li><a href="#">Node.js</a></li>
      <li><a href="#">Java</a></li>
    </ul>
  </nav>

</body>

</html>
